Effect of support characteristics on the earth pressure in a jointed rock mass

Abstract

This study examines the magnitude and distribution of earth pressures against a support system in a jointed rock mass according to the support characteristics (strut stiffness and spacing), different rock types, and joint conditions (joint shear strength and joint inclination angle). A series of numerical parametric analyses were performed after verifying the numerical approach through a physical model test. These analyses were based on the discrete element method, which can take into account the joint characteristics of the rock strata and the interactions between the ground and the retaining structure. The results were compared with Peck’s earth pressure for soil ground, which showed that the magnitude and distribution of earth pressure are strongly affected by the support characteristics, rock types, and joint conditions, and that the earth pressure in the rock stratum can be significantly different from that in the soil ground. The results suggest that the support characteristics, including the rock types and joint conditions, are important factors affecting the earth pressure, and should be considered for the safe and economic design and construction of retaining structures in a jointed rock mass.